Highly Sensitive pH Sensing Using an Indium Nitride Ion-Sensitive Field-Effect Transistor

Chang, Yu‐Chi; Lu, Yi; Hong, Yu-Liang; Gwo, Shangjr; Yeh, J. Andrew

doi:10.1109/jsen.2010.2080317

Cited by 40 publications

(25 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…13 with minimal external components. Equation (11) describes the bottom plate voltage (V bias ) of the EISCAP that is set from the firmware using two 8 bit Digital-to-Analog-Converters (DACs). DAC 1 and DAC 2 are referred to as the fine and coarse DAC respectively.…”

Section: B System-on-chip Implementationmentioning

confidence: 99%

A Miniaturized pH Sensor With an Embedded Counter Electrode and a Readout Circuit

et al. 2013

View full text Add to dashboard Cite

Electrolyte insulator semiconductor capacitors (EISCAPs) show a shift in the measured capacitance-voltage (C-V) characteristics with changes in the pH of the electrolyte and has the potential to be used as biosensors. The choice of an electrode to the EISCAP is important for reliable measurements. Here, we discuss a silicon-based EISCAP sensor bonded to a glass wafer with an embedded electrode. Three noble metal electrodes (Pt, Au, Ag) are studied for the ease of integration and performance and it is found that the chloridized Ag electrodes exhibit the highest pH sensitivity and the lowest electrode potential drift with time. A readout system that measures the pH of the electrolyte under test is developed and implemented in a programmable system on chip. Calibration of the EISCAP to account for sensor process variations is also incorporated. The pH measurement data on the miniaturized EISCAPs is presented.Index Terms-Biosensor, bonding, electrode integration, electrolyte insulator semiconductor capacitor (EISCAP), micromachining, miniaturization, pH sensing, thin film Ag-AgCl.

show abstract

Section: B System-on-chip Implementationmentioning

confidence: 99%

A Miniaturized pH Sensor With an Embedded Counter Electrode and a Readout Circuit

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Both devices have almost the same properties such as high input and low output impedances. Although VDBA has voltage as input but it has a distinct advantage of providing properties of current mode circuit such as greater bandwidth, lower power consumption, higher slew rate and wider linearity compared to OPAMP [4][5][6][7]. The main difference between VDBA and OTA is that VDBA has low output impedance that is more suitable than voltage-mode circuit because there is complete elimination of loading effect.…”

Section: Introductionmentioning

confidence: 99%

CMOS Integrated VDBA-ISFET Device for Water Quality Monitoring

Whig¹,

Ahmad²

2014

IJIES

View full text Add to dashboard Cite

The paper presents a performance analysis of low power CMOS Integrated "Voltage Differencing Buffered Amplifier Ion Sensitive Field Effect Transistor" (VDBA-ISFET). The main focus is on simulation of power and performance analysis along with the comparison with existing devices, which is used for water quality monitoring. This approach can improve the calibration of device to a fairly wide range without the use of a high speed digital processor. The conventional devices generally used consume high power and are not stable for long term monitoring. The conventional device has a drawback of low value of slew rate, high power consumption, and non linear characteristics but in this novel design, the device exhibits a better slew rate, piece-wise linear characteristics, and seen consuming low power of the order of 11.3µW. The functionality of the circuit is tested using Tanner simulator version 15 for CMOS process model. The proposed circuit reduces total power consumption per cycle, increases speed of operation, fairly linear and is simple to implement.This device has a simple architecture, and hence is very suitable for water quality monitoring applications.

show abstract

“…In the last decade the interest in nitride-based sensors has increased both in the field of gas and ion-detection [4][5][6][7][8][9][10][11], especially since the first evidence of pH-sensitivity of GaN surfaces [6] and its application in pH-sensitive AlGaN/GaN field effect transistors [7]. In particular, the Ga x O y on the surface (native or promoted by wet oxidation) seems to follow the site-binding model [12] that explains the pH sensitivity.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, the Ga x O y on the surface (native or promoted by wet oxidation) seems to follow the site-binding model [12] that explains the pH sensitivity. Compared to standard dielectric materials such as SÍO2, SÍ3N4 and AI2O3 used in commercial ISFET, improved sensitive response and robust surface properties can be ascribed to nitride materials like GaN [7] and InN [8]. Especially for chemical and biomedical applications in harsh environments, nitride robustness can be a solution to avoid or reduce possible damages and contaminations.…”

Section: Introductionmentioning

confidence: 99%

Investigation of AlInN barrier ISFET structures with GaN capping for pH detection

Brazzini¹,

Bengoechea-Encabo²,

Sánchez-García³

et al. 2013

Sensors and Actuators B: Chemical

View full text Add to dashboard Cite

The pH response of GaN/AlInN/AlN/GaN ion-sensitive field effect transistor (ISFET) on Si substrates has been characterized. We analyzed the variation of the surface potential (AV sp /ApH) and current (A/ ds /ApH) with solution pH in devices with the same indium content (17%, in-plane lattice-matched to GaN) and different AlInN thickness (6 nm and 10 nm), and compared with the literature. The shrinkage of the barrier, that has the effect to increase the transconductance of the device, makes the 2-dimensional electron density (2DEG) at the interface very sensitive to changes in the surface.Although the surface potential sensitivity to pH is similar in the two devices, the current change with pH (A/ds/ApH), when biasing the ISFET by a Ag/AgCl reference electrode, is almost 50% higher in the device with 6nm AlInN barrier, compared to the device with lOnm barrier. When measuring the current response (A/ ds /ApH) without reference electrode, the device with thinner AlInN layer has a larger response than the thicker one, of a factor of 140%, and that current response without reference electrode is only 22% lower than its maximum response obtained using reference electrode.

show abstract

Highly Sensitive pH Sensing Using an Indium Nitride Ion-Sensitive Field-Effect Transistor

Cited by 40 publications

References 26 publications

A Miniaturized pH Sensor With an Embedded Counter Electrode and a Readout Circuit

A Miniaturized pH Sensor With an Embedded Counter Electrode and a Readout Circuit

CMOS Integrated VDBA-ISFET Device for Water Quality Monitoring

Investigation of AlInN barrier ISFET structures with GaN capping for pH detection

Contact Info

Product

Resources

About